Transceivers comprise a radio transmitter and a radio receiver combined in a single unit with a switch to permit both transmission and reception of signals. In designing a transceiver, it is highly desirable to utilize a single antenna for sending and receiving. However, using the same antenna for transmitting and receiving presents a number of problems.
The principle problem for a single antenna design is the trade-off between sufficient sensitivity for receiving signals and maintaining manageable voltage levels and losses for transmitting. In order to provide sufficient sensitivity for receiving signals, it is desirable to increase the number of turns (wire) in the antenna. While increasing the number of turns improves the sensitivity for reception, higher voltage levels are required to drive the additional turns when the antenna is used for the transmission of signals. There are also the associated electrical losses in the turns of the coil for the antenna. Since most transceivers are battery powered, power needs and losses are an important design consideration.
Accordingly, there remains a need for antenna configuration suitable for a transceiver which overcomes these problems.